Removal of Cr ⁶⁺ ions from water by electrosorption on modified activated carbon fibre felt

Abstract

Electrosorption is a novel desalination technique that has many advantages in the treatment of sewage. However, commercially available activated carbon electrodes for electrosorption commonly have low microporosity, poor moulding performance, and low adsorption and regeneration efficiency. Here, we evaluated a novel adsorbent material, activated carbon fibre felt (ACFF), for electrosorption of chromium ions (Cr6+) in sewage treatment. The ACFF was modified with 20% nitric acid and its modified structure was characterized. The modified ACFF was used as an adsorbing electrode to investigate its desalination effect by electrosorption. Results showed that compared with those of unmodified ACFF, the modified ACFF had more carbonyl and carboxyl groups and the specific surface area, average pore size and micropore volume of the modified ACFF also improved by 32.2%, 2.5% and 23.1%, respectively. The kinetics of Cr6+ adsorption conformed to the pseudo-second-order kinetic equation, and the adsorption isotherm conformed to the Langmuir model. In addition, the regeneration rate of the modified ACFF electrode was more than 94%. In conclusion, the modified ACFF exhibits excellent electrosorption and regeneration performance for Cr6+ removal from water and thus is of great value for promotion in sewage treatment.

Agricultural waste of sugarcane bagasse as efficient adsorbent for lead and nickel removal from untreated wastewater: Biosorption, equilibrium isotherms, kinetics and desorption studies

“…The results obtained in this study were in agreement with previous studies, which also reported that the adsorption process followed the pseudo-second-order kinetics [ 38 , 60 , 67 ]. Adsorption kinetics is an important factor in describing rate of reaction and principal mechanisms involved in adsorption [ 28 ].…”

Valorization of spent disposable wooden chopstick as the CO2 adsorbent for a CO2/H2 mixed gas purification

“…The peaks found at a wavenumber of 1650–1800 cm −1 were attributed to the presence of the C=O stretching vibration of carboxylic and lactones. Intense spectra appeared a wavenumber of 2300–2400 cm −1 due to atmospheric CO 2 53 , 54 . After steam activation, qualitative changes were observed in all six ACs, from which some bands were diminished.…”

Anti-microbial and methylene blue dye adsorption properties of cotton fabrics modified with TiO2, Fe, Ag-doped TiO2, and graphene oxide nanomaterials

“…The good fitting line of the pseudo-second-order model shown in Figure 8(b) indicates that the adsorption – the determining factor of the MB elimination – may be involved in the chemisorption. 129…”

“…The good fitting line of the pseudo-second-order model shown in Figure 8(b) indicates that the adsorption -the determining factor of the MB elimination -may be involved in the chemisorption. 129 Figure 9(a) shows the fitting plots of the secondorder model, (1/(q e -q t ) versus t). The values of q e , k 2 , and R 2 were determined and are listed in Table 5.…”